Alert archive / Pennsylvania / Areal Flood Advisories in 2018
Areal Flood Advisory 266, NWS Philadelphia/Mount Holly
NWS Philadelphia/Mount Holly issued this areal flood advisory at Aug 31, 2018, 10:14 AM EDT for Chester County, Pennsylvania. It was in force for 3 hr.
The area
The counties it named.
The facts
- Issued
- Aug 31, 2018, 10:14 AM EDT (14:14 UTC)
- Expired
- Aug 31, 2018, 1:15 PM EDT
- In force
- 3 hr
- Issued by
- NWS Philadelphia/Mount Holly
- Area
- Storm-based polygon
County Chester County, PA
The radar
The Philadelphia radar (KDIX), 114 km from the middle of the area, began a volume at 14:16 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Washington/Dulle, VA (KIAD), launched 12:00Z, 2.2 hours before the alert went out and 182 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 425 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 930 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 68 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Philadelphia/Mount Holly wrote its last area forecast discussion before this areal flood advisory went out at Aug 31, 9:53 AM EDT, 21 minutes earlier.
Area forecast discussion, Aug 31, 9:53 AM EDT, 21 minutes before
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</html>Hazardous weather outlook, Aug 31, 5:20 AM EDT, 4 hours 54 minutes before
Hazardous Weather Outlook National Weather Service Mount Holly NJ 520 AM EDT Fri Aug 31 2018 NJZ001-007>010-012-PAZ054-055-061-062-010930- Sussex-Warren-Morris-Hunterdon-Somerset-Middlesex-Carbon-Monroe- Lehigh-Northampton- 520 AM EDT Fri Aug 31 2018 This Hazardous Weather Outlook is for northern New Jersey, northwest New Jersey, east central Pennsylvania and northeast Pennsylvania. .DAY ONE...Today and Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. DEZ001>003-MDZ008-012-015-019-020-NJZ013-015>023-027-PAZ060-070-071- 101>106-010930- New Castle-Kent-Inland Sussex-Cecil-Kent MD-Queen Annes-Talbot- Caroline-Western Monmouth-Mercer-Salem-Gloucester-Camden- Northwestern Burlington-Ocean-Cumberland-Atlantic-Cape May- Southeastern Burlington-Berks-Delaware-Philadelphia-Western Chester- Eastern Chester-Western Montgomery-Eastern Montgomery-Upper Bucks- Lower Bucks- 520 AM EDT Fri Aug 31 2018 This Hazardous Weather Outlook is for central Delaware, northern Delaware, southern Delaware, northeast Maryland, central New Jersey, southern New Jersey, east central Pennsylvania and southeast Pennsylvania. .DAY ONE...Today and Tonight. Some showers and thunderstorms today will be capable of very heavy downpours leading to localized flooding especially in poor drainage areas. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. DEZ004-NJZ014-024>026-010930- Delaware Beaches-Eastern Monmouth-Atlantic Coastal Cape May- Coastal Atlantic-Coastal Ocean- 520 AM EDT Fri Aug 31 2018 This Hazardous Weather Outlook is for southern Delaware, central New Jersey and southern New Jersey. .DAY ONE...Today and Tonight. There is a moderate risk for the formation of dangerous rip currents along the New Jersey shore and the Delaware Beaches through this evening. Some showers and thunderstorms today will be capable of very heavy downpours leading to localized flooding especially in poor drainage areas. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. ANZ450>455-010930- Coastal waters from Sandy Hook to Manasquan Inlet NJ out 20 nm- Coastal waters from Manasquan Inlet to Little Egg Inlet NJ out 20 nm- Coastal waters from Little Egg Inlet to Great Egg Inlet NJ out 20 nm- Coastal waters from Great Egg Inlet to Cape May NJ out 20 nm- Coastal waters from Cape May NJ to Cape Henlopen DE out 20 nm- Coastal waters from Cape Henlopen to Fenwick Island DE out 20 nm- 520 AM EDT Fri Aug 31 2018 This Hazardous Weather Outlook is for Atlantic coastal waters. .DAY ONE...Today and Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures. ANZ430-431-010930- Delaware Bay waters north of East Point NJ to Slaughter Beach DE- Delaware Bay waters south of East Point NJ to Slaughter Beach DE- 520 AM EDT Fri Aug 31 2018 This Hazardous Weather Outlook is for Delaware Bay Waters. .DAY ONE...Today and Tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to standard operating procedures.
In the hours before
Local storm report, Aug 31, 7:34 AM EDT, 2 hours 40 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
734 AM EDT FRI AUG 31 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0719 AM HEAVY RAIN SOUTHAMPTON TWP 39.91N 74.73W
08/31/2018 M3.58 INCH BURLINGTON NJ TRAINED SPOTTER
&&
EVENT NUMBER PHI1801457
DAVISLocal storm report, Aug 31, 8:57 AM EDT, 1 hour 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
857 AM EDT FRI AUG 31 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0850 AM HEAVY RAIN 1 ESE THORNBURY TWP 39.91N 75.54W
08/31/2018 M2.00 INCH DELAWARE PA TRAINED SPOTTER
RAINFALL IN THORNTON IN 45 MINUTES.
&&
EVENT NUMBER PHI1801458
GORSELocal storm report, Aug 31, 10:08 AM EDT, 6 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1008 AM EDT FRI AUG 31 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0845 AM FLASH FLOOD THORNBURY TWP 39.93N 75.50W
08/31/2018 DELAWARE PA TRAINED SPOTTER
NUMEROUS ROADS IMPASSABLE DUE TO FLASH FLOODING IN
THORNBURY TOWNSHIP WEST OF CHENEY ROAD. PICTURE ON
SOCIAL MEDIA SHOWED FLOOD WATERS FLOWING ACROSS A
ROADWAY. 2 INCHES OF RAIN FELL WITHIN 45 MINUTES.
&&
EVENT NUMBER PHI1801459
GORSEThe office that day
Everything else NWS Philadelphia/Mount Holly issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 5:17 AM EDT | Areal Flood Advisory | PHI | Burlington | 3 hr |
| Aug 31, 5:36 AM EDT | Flash Flood Warning | PHI | Burlington | 3 hr |
| Aug 31, 6:27 AM EDT | Flash Flood Warning | PHI | Burlington | 3 hr |
| Aug 31, 6:37 AM EDT | Severe Thunderstorm Warning | PHI | Burlington, Ocean | 53 min |
| Aug 31, 7:34 AM EDT | Areal Flood Advisory | PHI | Atlantic, Burlington, Camden | 2 hr |
| Aug 31, 9:29 AM EDT | Areal Flood Advisory | PHI | Burlington | 119 min |
| Aug 31, 12:47 PM EDT | Special Marine Warning | PHI | 118 min | |
| Aug 31, 1:22 PM EDT | Areal Flood Advisory | PHI | Morris, Sussex, Warren | 4 hr |
| Aug 31, 4:30 PM EDT | Special Marine Warning | PHI | 90 min | |
| Aug 31, 6:52 AM EDT | Areal Flood Advisory | PHI | Philadelphia | 4 hr |
| Aug 31, 7:55 AM EDT | Areal Flood Advisory | PHI | Delaware | 3 hr |
| Aug 31, 10:09 AM EDT | Flash Flood Warning | PHI | Berks | 7 hr |
| Aug 31, 1:54 PM EDT | Areal Flood Advisory | PHI | Berks, Chester, Lehigh, Montgomery | 4 hr |
| Aug 31, 3:59 PM EDT | Flash Flood Warning | PHI | Berks, Chester | 4 hr |
| Aug 31, 5:13 PM EDT | Areal Flood Warning | PHI | Berks | 7 hr |
| Aug 31, 1:37 AM EDT | Special Weather Statement | PHI | Sussex | 53 min |
| Aug 31, 10:57 AM EDT | Areal Flood Advisory | PHI | Kent | 107 min |
| Aug 31, 11:31 AM EDT | Flash Flood Warning | PHI | Kent | 11 hr |
| Aug 31, 11:53 AM EDT | Special Weather Statement | PHI | Kent | 37 min |
| Aug 31, 12:00 PM EDT | Severe Thunderstorm Warning | PHI | Kent | 15 min |
| Aug 31, 12:15 PM EDT | Flash Flood Warning | PHI | Kent, Sussex | 7 hr |
| Aug 31, 12:28 PM EDT | Special Weather Statement | PHI | Kent | 32 min |
| Aug 31, 12:35 PM EDT | Severe Thunderstorm Warning | PHI | Kent, Sussex | 40 min |
| Aug 31, 12:54 PM EDT | Flash Flood Warning | PHI | Sussex | 4 hr |
| Aug 31, 1:09 PM EDT | Severe Thunderstorm Warning | PHI | Sussex | 51 min |
| Aug 31, 1:58 PM EDT | Special Weather Statement | PHI | Sussex | 32 min |
| Aug 31, 4:27 PM EDT | Special Weather Statement | PHI | Sussex | 18 min |
| Aug 31, 4:32 PM EDT | Flash Flood Warning | PHI | Sussex | 4 hr |
| Aug 31, 4:41 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle | 4 hr |
| Aug 31, 4:42 PM EDT | Special Weather Statement | PHI | Sussex | 33 min |
| Aug 31, 5:00 PM EDT | Flash Flood Warning | PHI | New Castle | 4 hr |
| Aug 31, 5:14 PM EDT | Special Weather Statement | PHI | Sussex | 46 min |
| Aug 31, 5:38 PM EDT | Areal Flood Advisory | PHI | Kent, New Castle, Sussex | 4 hr |
| Aug 31, 5:48 PM EDT | Flash Flood Warning | PHI | Sussex | 3 hr |
| Aug 31, 7:11 PM EDT | Areal Flood Warning | PHI | Kent, Sussex | 4 hr |
| Aug 31, 7:37 PM EDT | Flash Flood Warning | PHI | Kent, New Castle | 4 hr |
Nearby
Areal Flood Advisories in Pennsylvania, 2018Every areal flood advisory in 2018
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.